It has just released confidential documents that shed light on the war in Afghanistan, but how has Wikileaks become one of the most important whistle-blowing sites on the web?

The news that the largest leak in American military history came via the website Wikileaks will not surprise long-term watchers of the controversial, multi-award-winning site.

Despite a recent period of near-bankruptcy, it has consistently released information that major corporations and governments wanted to conceal – the Abu Ghraib “torture manual”, footage from American jets allegedly committing war crimes, the secrets of Scientology and even Sarah Palin’s private emails have all been published by the site.

Founded by secretive Australian Julian Assange, Wikileaks was originally based in Sweden and garnered 1.2 million leaked documents in time for its launch in January 2007.

It taps in to the world’s web users’ desire either for justice or revenge on former employers or acquaintances, but its most significant stories have been held up as largely in the public interest.

The Abu Ghraib revelations resulted in international condemnation of American methods and arguably contributed to political commitments from Barack Obama to close down the detention centre.

Assange claims that by using the global community of internet users, his site is able to promote accuracy, scrutiny and discussion of sensitive information.

Anybody with web access can submit a story to Wikileaks. The site, however, states that its "primary interest is in exposing oppressive regimes in Asia, the former Soviet bloc, sub-saharan Africa and the Middle East, but we also expect to be of assistance to people of all regions who wish to reveal unethical behaviour in their governments and corporations."

Wikileaks has now evolved an editorial policy by which only documents "of political, diplomatic, historical or ethical interest" are in fact published, and it has recently ceased to permit users to comment directly on stories.

Earlier this year, Assange said that submissions are vetted by five reviewers, and that the background of the “leaker” is also checked.

A number of countries and companies, notably Australia, China and Bank Julius Baer have tried to censor the site or have it taken offline, but its complex method of web-hosting has ensured that it is very difficult for its servers to be identified.

Wikileaks has also used a Swedish company called PRQ, which specialises in “bulletproof hosting”, asking no questions and maintaining few records of its clients so that it cannot be accused of promoting material that could be illegal.

The site has been heavily criticised in the past for endangering the lives of individuals, just as American and Pakistani representatives have said this latest leak of American military logs will too.

But only last weak Assange told America’s Wired magazine that Wikileaks was "getting an enormous quantity of whistle-blower disclosures of high calibre".

The only reason more has not been released was a lack of volunteer journalists to verify the submissions, he said, adding that BP was set to be one of his site’s future subjects.